Why does nom expect a &str when I pass a CompleteStr?












0















The parser works as expected until I want to parse the h: digit which is always the last digit in the string and the compiler gives me



^ expected &str, found struct `nom::types::CompleteStr`


I assume it's because the parser is looking ahead. How do I stop that, or how can I signify it's done?



#[macro_use]
extern crate nom;

use nom::digit;
use nom::types::CompleteStr;
use std::str::FromStr;

#[derive(Debug, PartialEq)]
pub struct Order {
pub l: u64,
pub w: u64,
pub h: u64,
}

named!(order_parser<CompleteStr, Order>,
do_parse!(
l: map_res!(digit, u64::from_str) >>
tag!("x") >>
w: map_res!(digit, u64::from_str) >>
tag!("x") >>
h: map_res!(digit, u64::from_str) >>
(Order {l: l, w: w, h: h })
)
);

pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<&str>> {
order_parser(order)
}

#[test]
fn test_order_parser() {
assert_eq!(
wrap_order(CompleteStr("2x3x4")),
Ok((CompleteStr(""), Order { l: 2, w: 3, h: 4 }))
);
}









share|improve this question




















  • 1





    I believe your question is answered by the answers of Why does my nom parser not consume the entire input, leaving the last piece unparsed? / Parsing an integer with nom. If you disagree, please edit your question to explain the differences. Otherwise, we can mark this question as already answered.

    – Shepmaster
    Nov 20 '18 at 2:48











  • I changed it as I read up and still can't seem to get it to work

    – Pumphouse
    Nov 20 '18 at 4:29
















0















The parser works as expected until I want to parse the h: digit which is always the last digit in the string and the compiler gives me



^ expected &str, found struct `nom::types::CompleteStr`


I assume it's because the parser is looking ahead. How do I stop that, or how can I signify it's done?



#[macro_use]
extern crate nom;

use nom::digit;
use nom::types::CompleteStr;
use std::str::FromStr;

#[derive(Debug, PartialEq)]
pub struct Order {
pub l: u64,
pub w: u64,
pub h: u64,
}

named!(order_parser<CompleteStr, Order>,
do_parse!(
l: map_res!(digit, u64::from_str) >>
tag!("x") >>
w: map_res!(digit, u64::from_str) >>
tag!("x") >>
h: map_res!(digit, u64::from_str) >>
(Order {l: l, w: w, h: h })
)
);

pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<&str>> {
order_parser(order)
}

#[test]
fn test_order_parser() {
assert_eq!(
wrap_order(CompleteStr("2x3x4")),
Ok((CompleteStr(""), Order { l: 2, w: 3, h: 4 }))
);
}









share|improve this question




















  • 1





    I believe your question is answered by the answers of Why does my nom parser not consume the entire input, leaving the last piece unparsed? / Parsing an integer with nom. If you disagree, please edit your question to explain the differences. Otherwise, we can mark this question as already answered.

    – Shepmaster
    Nov 20 '18 at 2:48











  • I changed it as I read up and still can't seem to get it to work

    – Pumphouse
    Nov 20 '18 at 4:29














0












0








0








The parser works as expected until I want to parse the h: digit which is always the last digit in the string and the compiler gives me



^ expected &str, found struct `nom::types::CompleteStr`


I assume it's because the parser is looking ahead. How do I stop that, or how can I signify it's done?



#[macro_use]
extern crate nom;

use nom::digit;
use nom::types::CompleteStr;
use std::str::FromStr;

#[derive(Debug, PartialEq)]
pub struct Order {
pub l: u64,
pub w: u64,
pub h: u64,
}

named!(order_parser<CompleteStr, Order>,
do_parse!(
l: map_res!(digit, u64::from_str) >>
tag!("x") >>
w: map_res!(digit, u64::from_str) >>
tag!("x") >>
h: map_res!(digit, u64::from_str) >>
(Order {l: l, w: w, h: h })
)
);

pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<&str>> {
order_parser(order)
}

#[test]
fn test_order_parser() {
assert_eq!(
wrap_order(CompleteStr("2x3x4")),
Ok((CompleteStr(""), Order { l: 2, w: 3, h: 4 }))
);
}









share|improve this question
















The parser works as expected until I want to parse the h: digit which is always the last digit in the string and the compiler gives me



^ expected &str, found struct `nom::types::CompleteStr`


I assume it's because the parser is looking ahead. How do I stop that, or how can I signify it's done?



#[macro_use]
extern crate nom;

use nom::digit;
use nom::types::CompleteStr;
use std::str::FromStr;

#[derive(Debug, PartialEq)]
pub struct Order {
pub l: u64,
pub w: u64,
pub h: u64,
}

named!(order_parser<CompleteStr, Order>,
do_parse!(
l: map_res!(digit, u64::from_str) >>
tag!("x") >>
w: map_res!(digit, u64::from_str) >>
tag!("x") >>
h: map_res!(digit, u64::from_str) >>
(Order {l: l, w: w, h: h })
)
);

pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<&str>> {
order_parser(order)
}

#[test]
fn test_order_parser() {
assert_eq!(
wrap_order(CompleteStr("2x3x4")),
Ok((CompleteStr(""), Order { l: 2, w: 3, h: 4 }))
);
}






rust nom






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share|improve this question








edited Nov 20 '18 at 15:50









Shepmaster

155k14307452




155k14307452










asked Nov 20 '18 at 1:22









PumphousePumphouse

1,2261122




1,2261122








  • 1





    I believe your question is answered by the answers of Why does my nom parser not consume the entire input, leaving the last piece unparsed? / Parsing an integer with nom. If you disagree, please edit your question to explain the differences. Otherwise, we can mark this question as already answered.

    – Shepmaster
    Nov 20 '18 at 2:48











  • I changed it as I read up and still can't seem to get it to work

    – Pumphouse
    Nov 20 '18 at 4:29














  • 1





    I believe your question is answered by the answers of Why does my nom parser not consume the entire input, leaving the last piece unparsed? / Parsing an integer with nom. If you disagree, please edit your question to explain the differences. Otherwise, we can mark this question as already answered.

    – Shepmaster
    Nov 20 '18 at 2:48











  • I changed it as I read up and still can't seem to get it to work

    – Pumphouse
    Nov 20 '18 at 4:29








1




1





I believe your question is answered by the answers of Why does my nom parser not consume the entire input, leaving the last piece unparsed? / Parsing an integer with nom. If you disagree, please edit your question to explain the differences. Otherwise, we can mark this question as already answered.

– Shepmaster
Nov 20 '18 at 2:48





I believe your question is answered by the answers of Why does my nom parser not consume the entire input, leaving the last piece unparsed? / Parsing an integer with nom. If you disagree, please edit your question to explain the differences. Otherwise, we can mark this question as already answered.

– Shepmaster
Nov 20 '18 at 2:48













I changed it as I read up and still can't seem to get it to work

– Pumphouse
Nov 20 '18 at 4:29





I changed it as I read up and still can't seem to get it to work

– Pumphouse
Nov 20 '18 at 4:29












1 Answer
1






active

oldest

votes


















4














The error is not on the last digit parser, it's on each of them (Rust 1.30.0 prints the error three times). That's because u64::from_str works on &str, not CompleteStr.



You can fix your parsers to use u64::from_str correctly this way:



do_parse!(
l: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
tag!("x") >>
w: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
tag!("x") >>
h: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
(Order { l: l, w: w, h: h })
)


There are also some unrelated error with the next function, which can be fixed by using the appropriate types in the signature:



pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<CompleteStr>> {
order_parser(CompleteStr(order))
}





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    4














    The error is not on the last digit parser, it's on each of them (Rust 1.30.0 prints the error three times). That's because u64::from_str works on &str, not CompleteStr.



    You can fix your parsers to use u64::from_str correctly this way:



    do_parse!(
    l: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
    tag!("x") >>
    w: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
    tag!("x") >>
    h: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
    (Order { l: l, w: w, h: h })
    )


    There are also some unrelated error with the next function, which can be fixed by using the appropriate types in the signature:



    pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<CompleteStr>> {
    order_parser(CompleteStr(order))
    }





    share|improve this answer






























      4














      The error is not on the last digit parser, it's on each of them (Rust 1.30.0 prints the error three times). That's because u64::from_str works on &str, not CompleteStr.



      You can fix your parsers to use u64::from_str correctly this way:



      do_parse!(
      l: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
      tag!("x") >>
      w: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
      tag!("x") >>
      h: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
      (Order { l: l, w: w, h: h })
      )


      There are also some unrelated error with the next function, which can be fixed by using the appropriate types in the signature:



      pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<CompleteStr>> {
      order_parser(CompleteStr(order))
      }





      share|improve this answer




























        4












        4








        4







        The error is not on the last digit parser, it's on each of them (Rust 1.30.0 prints the error three times). That's because u64::from_str works on &str, not CompleteStr.



        You can fix your parsers to use u64::from_str correctly this way:



        do_parse!(
        l: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
        tag!("x") >>
        w: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
        tag!("x") >>
        h: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
        (Order { l: l, w: w, h: h })
        )


        There are also some unrelated error with the next function, which can be fixed by using the appropriate types in the signature:



        pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<CompleteStr>> {
        order_parser(CompleteStr(order))
        }





        share|improve this answer















        The error is not on the last digit parser, it's on each of them (Rust 1.30.0 prints the error three times). That's because u64::from_str works on &str, not CompleteStr.



        You can fix your parsers to use u64::from_str correctly this way:



        do_parse!(
        l: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
        tag!("x") >>
        w: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
        tag!("x") >>
        h: map_res!(digit, |CompleteStr(s)| u64::from_str(s)) >>
        (Order { l: l, w: w, h: h })
        )


        There are also some unrelated error with the next function, which can be fixed by using the appropriate types in the signature:



        pub fn wrap_order(order: &str) -> Result<(CompleteStr, Order), nom::Err<CompleteStr>> {
        order_parser(CompleteStr(order))
        }






        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Nov 21 '18 at 18:52

























        answered Nov 20 '18 at 8:31









        Valentin LorentzValentin Lorentz

        6,77253555




        6,77253555
































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